As Chuck Klosterman wrote in Sex, Drugs, and Cocoa Puffs, nerds owe everything about their love lives to Woody Allen, even if Woody Allen's work isn't even familiar to people nowadays:

Woody Allen changed everything. Woody Allen made it acceptable for beautiful women to sleep with nerdy, bespectacled goofballs; all we need to do is fabricate the illusion of intellectual humor, and we somehow have a chance. The irony is that many of the women most susceptible to this scam haven't even seen any of Woody's movies, nor would they want to touch the actual Woody Allen if they ever had the chance (especially since he's proven to be an über-pervy clarinet freak). If asked, most of these foxy ladies wouldn't classify Woody Allen as sexy, or handsome, or even likable. But this is how media devolution works: It creates an archetype that eventually dwarfs its origin. By now, the "Woody Allen Personality Type" has far greater cultural importance than the man himself.

I myself am not that familiar with Woody Allen's ouevre, although I'm a fan of his writing (my favorite is a story called The Intellectual Whore of Mensa. I'd seen some of his latest work (most of them were mediocre, except for Match Point), and I'm sure it's true for most people reading this. Fortunately, the AV Club has an extensive primer for the Woody Allen newbie, discussing the director's work, what to watch, and what to skip. Annie Hall, for which Allen won Oscars for Best Picture, Best Director, and Best Screenplay, was the movie that created the archetype Klosterman describes above:

The breadth of Annie Hall's influence can't be overstated. It's the birth of a modern-day American romantic comedy, where relationships are forged via banter-filled walk-and-talks and the male lead's idea of courtship is an extended stand-up routine. Annie Hall is to romantic comedies as Halloween is to slasher films—a great achievement that spawned a lot of bad movies.

The latest Woody Allen film, Vicky Christina Barcelona is getting a buzz because of a love scene between film stars Scarlett Johansson and Penelope Cruz. Curiously, the film has gotten the best reviews for a Woody Allen in a while.